This invention relates generally to an improved cutting die for sealing or waterproofing corrugated board to produce for example an improved waterproof corrugated box for use in the Hydro-cooling process, the box having all of its exposed edges sealed by means of the cutting die of the present invention.
In order to slow down the decay rate of produce and/or fruit to allow the produce and/or fruit to reach the market place in a fresh and prime condition, the process of Hydro-cooling was developed. Basically, this process is used by the produce and/or fruit growers and packers wherein the product to be shipped is placed in a shipping container or box which then goes through a bath and/or shower of ice water anywhere from three minutes to one hour depending upon the type of product in the box. The purpose of the ice water bath is to super cool the product prior to shipment.
Since most of the boxes in which these products are shipped are made from corrugated paper, problems have been encountered using standard corrugated paper boxes for the shipping container since the paper often got soft and pulpy after contact with the water and moisture. In attempting to develop improved boxes in the laboratory, it was found that by coating the container with a wax impregnation and coating certain of the exposed edge surfaces of the box that a somewhat acceptable job of creating a usable container was accomplished.
When the wax impregnated boxes were tested in the laboratory, it was observed that, under Hydro-cooling process water conditions, the water impregnated between the inner and outer liners of the corrugated box through seepage from exposed edges thereby soaking into the corrugating medium and softening it thereby allowing the box to collapse. Other box manufactures have attempted to solve this problem by the use of corrugated board constructions comprising a pair of corrugated inner sheets having been laminated together with an asphalt wax composition. One such construction is shown in the U.S. Pat. No. 3,579,413 issued May 18, 1971, to Russell E. Koons. This type of corrugated construction, while being of beneficial use as a waterproof container in itself, was not found to completely solve the problem since the process water often seeped through the exposed edges of the box and through the exposed edges of the holes contained within the box resulting in eventual box collapse.